This invention relates to apparatus and a method for cleaning of machines that are used for filling containers such as bottles. The term "bottles" will be used herein as a generic term for all types of containers that can be filled with the machine.
A commonly used type of bottle filling machine comprises a stationary floor mounted frame which supports a shaft that is rotatable under power about a vertical axis. A rotor ring is driven by the shaft and is supported on thrust bearings that rest on the frame. A bowl or reservoir for the fluid product that is to be injected into the bottles is mounted to the top of the rotor ring and the bowl is supplied with counterpressure gas. Bottle filler valves are supported radially outwardly from the bowl and are connected to the bowl by means of a gas pipe and a fluid product pipe. A plurality of bottle supports or holders are mounted to the rotor ring through the agency of a pneumatic cylinder on which there is a cam follower which runs onto a single stationary cam at a certain time during rotor rotation to thereby extend the cylinder and lower the bottle holder for having a bottle placed on it. As the cylinder passes the cam, pneumatic pressure drives the bottle on the holder upwardly to engage its mouth with a centering bell which forms a seal so that the fluid product can be inserted in the bottle a moment later. After filling, the bottle holder and the bottle thereon ultimately arrives at the cam again at which time the holder is lowered, the filled bottle is removed and a new empty bottle is placed on the holder and the cycle repeats.
One known method for cleaning machines of this type requires that bottles be placed on the individual bottle platforms or holders for being pressed against the centering bell of the filling valve to thereby provide a liquid tight seal. Prior to this time, the lifting cam for the bottle holders is disengaged to enable the bottles to remain on the platforms or holders throughout full rotation of the rotor ring even in the infeed and discharge regions where the bottle holders or platforms are normally lifted and lowered, respectively.
When all of the bottles are pressed into the centering bells, the cleaning and disinfectant solution is pumped into the valves at high pressure which augments the cleaning process. It would, of course, be possible to substitute recirculating canisters for the standard beverage bottles during the cleaning process. A disadvantage of this method, however, is that it requires periodic removal of the cam which is not easy because the cam must be massively constructed and solidly mounted in order to withstand the high forces that result from the cam followers impacting it.
Another known machine cleaning method involves fastening canisters directly to the filler valve housings concentric to the counterpressure return tubes by means of a special type of releasable clamp or fastener. The containers are then rotated as they are during a normal filling process but they are clear of the lowered bottle holders so there is no interference in the infeed or discharge region. This method, however, does not effect a high sealing pressure between the filling valve and the canister and consequently does not permit circulation of cleaning and disinfecting solution at very high pressure. This known method also requires a canister mounting device on the valve which is not optimally simple in construction nor convenient to use.
The present invention relates to a device, namely, a canister that enables the cleaning operation to be performed without requiring removal or displacement of the cam which, during the normal bottle filling operation, raises and lowers the bottle platforms or holders.
In accordance with the invention, the vertically reciprocable bottle holders are constrained in a lowermost position wherein the cam follower rollers on the lifting cylinders completely clear the cam. Canisters are inserted on the holders and they have greater length than the bottles which the machine is adapted to fill. When the slightly greater length canisters are in place on all of the holders, the lift cylinders are actuated to drive the upper ends of the canisters in sealing relationship with the filler valve. However, the canisters are of such length that the cam follower rollers clear the entire profile of the stationary cam though the rotor can turn if desired. With this arrangement, the canisters can be driven into sealing relationship with the filler valves so that the cleaning solution can be delivered to all fluid conductive parts of the machine at very high pressure which assures good cleaning efficiency.
Since, for functional and safety reasons, the lowest point of the lift cylinders on most common filling machines is generally lower than the lowest point of the lift cam, no special modification of the filling machine is necessary in this case where the canisters have such length as to prevent the cam followers from touching the stationary cam.
The new method has several advantages. One is that the appropriately dimensioned cleaning-in-place (C.I.P.) canisters serve as spacers, thus eliminating the need for any special platform or bottle holding arresting blocks. Another advantage is that the canisters can be inserted effortlessly between the bottle holders and the filling valves after which the holders or platforms are lifted only slightly and pressed against the filling valves with a substantial force. The cleaning solution can then be routed through the valves into the canisters and returned. When the cleaning process is completed, the procedure is reversed where, after release of the pressure, the holders or bottle lifting platforms are returned to their lowest position and the canisters can be easily removed from the filling machine.
A significant advantage of the invention is that it can be applied to existing filling machines without difficulty since it is only necessary to make up canisters that have a somewhat greater length than the bottles which are normally filled in the particular filling machine.
How the foregoing and other objectives, features and advantages of the invention are achieved will be evident in the more detailed description of a preferred embodiment of the invention which will now be set forth in reference to the drawing.